SEOUL -- South Korea's ousted President Yoon Suk-yeol attended his first criminal trial on Monday on insurrection charges.

Yoon, carried by a black vehicle, arrived at the Seoul Central District Court at around 9:48 am local time (0048 GMT) and entered the courtroom via the court's underground parking lot in a bid to avoid public exposure, local media footage showed.

During the first formal hearing, Yoon reportedly denied his insurrection charges and defended himself by testifying in the courtroom for about 80 minutes. The second hearing was scheduled for April 21.

On April 4, the constitutional court upheld a motion by parliament to impeach Yoon over his short-lived martial law imposition.

With the court's decision, the conservative leader officially lost all presidential power, becoming the country's second elected president to be forcibly removed from power.

Yoon declared an emergency martial law on the night of Dec 3, 2024, but it was revoked by the opposition-led National Assembly hours later.

The impeachment motion against Yoon was passed in parliament on Dec 14, 2024.

Yoon was apprehended in the presidential office on Jan 15 and was indicted under detention on Jan 26 as a suspected ringleader of insurrection, becoming the country's first sitting president to be arrested and prosecuted.

If convicted of being the insurrection ringleader, Yoon could face the death penalty or life imprisonment.

He was released on March 8 as the prosecution decided not to appeal against a court's release approval.